(a) Field
The present application relates to a liquid crystal display.
(b) Description of the Related Art
A liquid crystal display is one of the flat panel displays which have been most widely used currently and includes two sheets of a display panel in which field generating electrodes, such as a pixel electrode and a common electrode, are formed and a liquid crystal layer interposed therebetween.
The field generating electrodes are applied with a voltage to generate an electric field in the liquid crystal layer and an alignment of liquid crystal molecules of the liquid crystal layer is determined and polarization of incident light is controlled based on the generated electric field to display an image.
The liquid crystal display further includes switching elements connected to each of the pixel electrodes and a plurality of signal lines, such as gate lines and data lines, which control the switching elements to apply a voltage to the pixel electrodes.
Among the liquid crystal displays, a liquid crystal display in a vertically aligned mode in which major axes of the liquid crystal molecules are aligned to be vertical to the display panel has a large contrast ratio and a wide reference viewing angle, and therefore has received much attention. Herein, a reference viewing angle means a viewing angle in which a contrast ratio is 1:10 or an inter-gray luminance inversion critical angle.
Meanwhile, in the case of the liquid crystal display according to the scheme, to make side visibility approximate front visibility, a method for making transmittance different by dividing one pixel into two sub-pixels and applying different voltages to the two sub-pixels has been suggested.
However, in the case of making side visibility approximate front visibility by dividing one pixel into two sub-pixels and making transmittance different, luminance is increased at a low gray or a high gray to make it difficult to implement gray expression at the side, thereby causing the problem that an image quality deteriorates.
Further, in the case of dividing one pixel only into a plurality of physical areas, a freedom of design is reduced to make it difficult to improve additional characteristics. Therefore, a method for improving additional characteristics by controlling a pretilt angle without changing a separate design is desired.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.